Two hydrogen
atoms each share their
1 electronwith oxygen
to form twocovalent bondsand make
a watermolecule (H2O).

This is a picture of a water
molecule.

By sharing the two electrons where the shells touch
each hydrogenatom can count 2 electrons in its outer shell
and the oxygenatom can count 8 electrons in its outer
shell.
These fullouter
shells with their shared electronsare now stable, and the
H2Omolecule willnotreact further with other oxygen
or hydrogen
atoms.

Note the 2
pairs (4 electrons)
shared between the atoms.
Each electron pair is one bond.
This
is called a singlecovalent bond.Water has two single covalent bonds.

The structural formula of a water molecule is writtenNote the shape of the
watermolecule,
with both hydrogens on the
same side of the oxygenatom.